Extreme claims require extreme scrutiny!!!

I am not a fan of any aftermarket ski.
I would rather you spend that money on a snowmobile trip.
10% of the time they may be better, but that's not worth $400.00

Darting can be fixed for only $10 - $15 dollars plus shipping.

Scott's Comments:
After selling, according to Curve, the most accurate and predictable snowmobile ski on the planet for one season. This statement may also apply in other galaxies. They have the nerve to come out with a product that is supposed to perform a function the skis were already supposed to perform. How can this be??? They must have known their skis did not perform as advertised yet they sold them.

SnowTech Magazine
December 2008
Page 76

Curve XS Skis

…a new ski that would solve many common problems such as darting, tracking, and pushing.

…Five years later, patents in pending, three distinct versions and thousands of trail and snow cross testing miles, has yielded a ski that is beyond anything they could have imagined.

It appears that their imagination was focussed more on their creative writing skills.

Page 78
… a truly incredible handling experience.

Page 78-79
…Due to the incredible abilities of these skis, the X configuration is integral and imperative.

To back it all up, extensive real world testing certifies all the computer predictions.

…They sell for $429. per set and come with your choice of loop color. A sled specific hardware and mount kit is $37.95 and makes for a no-shim, no washer installation.

American Snowmobiler
January 2009
Hot Products
Page 62

Curve Xtreme Ski System

…After 5 years of research and development, Curve has a ski that consistently puts your machine right where you want it, and with less effort.

Curves XS web site
October 16, 2009

Unlike anything you have seen before. We combined 3 revolutionary technologies to give you the most accurate and predictable snowmobile ski on the planet. Period.

(This statement may also apply in other galaxies.)

Curve Industries Releases The Leading Edge

Curve Industries announces the release of a revolutionary handling enhancement called the Leading Edge or LE. This patent pending device has been in the testing and development phases since 2008 but will be available to the public across a number of platforms in the first part of the 2010 riding season.

The leading edge was developed to address slow speed and deceleration tracking on rutted hard packed trails.

Curve Industries recommends the use of an LE on Curve XS skis only.

Retail pricing for the Leading Edge is targeted at $79.95/pr and includes instructions, mounting template and hardware.

Scott's Comments -

If the Curve XS Skis delivered everything they promised there would be no need for anything else to be added, to the ski. The truth is, on hardpacked snow and ice, the Curve XS skis work the same as all the other center keel skis, once a carbide wear rod is attached, because all the work is being done by the wear rod.

To get the effect of the bottom contour the snow would have to be deep enough, with enough water content, to form a rail. ( With the mount area level and a ½” carbide underneath, the outside edge at the widest point up front is 2 1/16” off the ground. The depth of the channel at that point is .135” in the front, .260" in the center and .120" in the rear.) Because the narrowest part of the channel is only approximately 6” long, ½” deep at the spindle bolt hole and 1 7/8” wide, flush with the outside edge, I find it hard to believe the snow would be compacted enough to achieve the effect they write about. I just don’t believe there is enough time, especially since the snow increases in speed through the narrower section of the channel, or enough pressure for any functional directional control to be achieved. Add to that, the keel rocker contact is only 2 1/2” long on the level.

I talked to a retired engineer who worked for Sundstrand Aviation and asked what he thought about Curves web site comments. He gave them an A on the creative writing but a F on meaningful content.

By the way, all skis have keels, bottom contours and front loops so you are forced to think in terms of a combination of the 3 parts when developing a ski.

Bergstrom BYO SKI | Dynamic Fluid Engaging Surface Patent 1992

Curve Ski

Unlike anything you have seen before. We combined 3 revolutionary technologies to give you the most accurate and predictable snowmobile ski on the planet. Period.

Snow Control
One of the most revolutionary features of this ski is the contact profile. By combining a constant radius center keel (Similar to the Polaris 2003 Saddleless ski) along with a carefully chosen side cut radius, a continuously variable outer cutting edge is created. With a continuously variable radius as part of the contact profile, snow velocities across the ski bottom change. This is an extremely desirable component when applied to the ski contact surface correctly.

Snow first enters the front of the ski where it meets the keel radius and beginning of the edge radius. As the snow progresses across the ski bottom toward the spindle pivot, the edge radius decreases, causing a drop in velocity and consequently, compaction. (sorry but it would increase the snows velocity, like any other venturi) Once the tight pivot radius is passed, the snow is expelled through an ejection radius that increases to the back of the ski. By correctly tailoring the intake area to the compaction area, a solid rail of snow is formed. Just as rails are used in roller coasters to rapidly divert forces of the cars in a different direction, our ski utilizes a similar energy transfer method. When snow is formed into a rail and compacted, it’s harder to sheer in a corner causing under steer or push. Likewise, it is more difficult to force a change of course while riding on a trail at high speeds, otherwise known as darting. (Simmons and Precision skis leave a rail of snow too but they do push in corners and will dart following similar profiles.) These are the premier concepts that have been focused on and refined to create a truly incredible handling experience.

X-Beam
This spindle mounting structure on the top face of ski is comprised of multiple complex geometric faces that have been molded with the ski. At the core of this layout is an X.. With an X positioned both forward and aft of the spindle, (similar to the 2003 Polaris saddleless ski) ski rigidity never before possible can be obtained. Bending moment and torsion couple resistance are immediate benefit of utilizing an X pattern on the ski face. When turning a 500 lb sled on a dime, tremendous forces are absorbed into the ski and must be transferred precisely to desired areas. The mounting structure plays an integral part of ensuring the turn is fluid and safe. Due to the incredible abilities of our ski, the X configuration is integral and imperative.

Another key benefit of our molded X structure is the ability to “trim the fat”. In other words, unneeded material is removed, whereby reducing weight, and weak areas are pin pointed and strengthened. Using computerized finite element analysis or FEA, ski can be placed in various operating conditions and modeled for results. Scenarios like diving into a hole can be simulated and played out with incredible accuracy. Deflection and spring back are then tailored by modifying different X structure characteristics. To back it all up, extensive real world testing certifies all the computer predictions.

Synergy (The front loop, bottom profile and keel of all plastic skis work in combination or in their word - system) (Simmons front slidable loop demonstrates that the only purpose loops serve is for pulling sleds out of the deep snow.) Chrysler snow-runner ski

Wrapping up the three unique features is one that has taken a great deal of time to perfect. The idea of a ski working as a system is one we focus on adamantly. We believe that a snowmobile ski is a series of individual components that must work synchronously together to form an active and dynamic system. In other words, all external inputs or forces placed on the ski, must have a channel of absorption that compliments the overall function and performance.

This idea was thoroughly in place when we designed our ski loop with a variable cross section. We understand that when the ski tip flexes to absorb an impact or contour, the ski loop must act as a shock absorber. (Simmons skis, V-Trac ski, and USI ski, Slydog ski. Every plastic ski flexes up front, from where the rigid part of the ski ends.) Instead of the loop limiting the ski tip in its motion, it simply compliments it, allowing unprecedented feedback to the rider.

Each component listed above has been designed and tested specifically to work as a system. Every curve, every radius, and every geometric feature of our skis exist in that form for a reason. That is why no matter what sled you ride or how hard you ride it, Curve Xtremes will redefine what accurate and predictable steering really is.

Scott's Comments:

Once you put a wear rod on Curve skis they are no different than any other ski on packed or icy snowmobile trails.

They have given no indication as to how deep and what water content the snow has to be to achieve their claimed benefit of the contours.

With the radius of the keel / ski, with just 2” of contact on the level, I am not sure there would be that much shearing resistance in snow. Not just the shortness of the compacted rail but where the edge radious is decreased to it’s narrowest point looks shallow enough for snow to squish out or overflow.

In deep snow they are also similar to other skis because deep snow is like riding in feathers or water. Skis do prevent the spindles from sticking like forks but it is the track that creates floatation. Turning is generated by the riders shifting their weight over the track.

I am not sure what they mean by a mounting structure! I read in a magazine that they have brand specific mounting kits, that do not need to be shimmed, for around $37.00. I am curious about this kit after examining the spindle pocket, all I saw were the spindle bolt holes.

Patent # 5,340,144 - filed –1992 Dynamic Fluid Engaging Surface for Vehicles